Particle emission induced by ionization tracks in water ice
نویسنده
چکیده
We study electron emission and sputtering during irradiation of amorphous water ice at 60 K by HC, DC, He+, Li+, Be+, B+, C+, N+, O+, F+, and Ne+ ions in the energy range from 10 to 100 keV. We find that for constant velocity (5 keV/amu) ions the dependence of the sputtering yields with projectile atomic number Z is proportional to the square of the Z-dependence of the electronic stopping power d E/dx, using dE/dx values predicted by Yarlagadda, Robinson, and Brandt. The electron yields increase sublinearly with dE/dx, indicating the strong influence of un-neutralized holes in the ionization track produced by the projectiles.
منابع مشابه
Microwave Radiation from Mixed Phase Cloud and Parameter Retrievals
The measurement of microwave radiation has been widely used in atmospheric remote sensing, such as temperature profiling, and vapor and liquid column measurements [1] [5]. The radiation from atmosphere is due to the absorption (emission) and scattering of electromagnetic (EM) wave by atmospheric particles (gaseous molecules, liquid water droplets and ice crystals). The absorption directly contr...
متن کاملUltrafast molecular dissociation of water in ice.
Using x-ray emission and photoemission spectroscopies to measure the occupied valence levels in a thin crystalline ice film, we resolve the ionization-induced dissociation of water in ice on a femtosecond time scale. Isotope substitution confirms proton transfer during the core-hole lifetime in spite of the nonresonant excitation. Through ab initio molecular dynamics on the core-ionized state, ...
متن کاملOn the potential contribution of open lead particle emissions to the central Arctic aerosol concentration
We present direct eddy covariance measurements of aerosol number fluxes, dominated by sub-50 nm particles, at the edge of an ice floe drifting in the central Arctic Ocean. The measurements were made during the ice-breaker borne ASCOS (Arctic Summer Cloud Ocean Study) expedition in August 2008 between 2–10 W longitude and 87–87.5 N latitude. The median aerosol transfer velocities over different ...
متن کاملPhotochemistry of polycyclic aromatic hydrocarbons in cosmic water ice II. Near UV/VIS spectroscopy and ionization rates
Context. Mid-infrared emission features originating from polycyclic aromatic hydrocarbons (PAHs) are observed towards photon dominated regions in space. Towards dense clouds, however, these emission features are quenched. Observations of dense clouds show that many simple volatile molecules are frozen out on interstellar grains, forming thin layers of ice. Recently, observations have shown that...
متن کاملLight emission from particle beam induced plasma: An overview
Experiments to study the light emission from plasma produced by particle beams are presented. Fundamental aspects in comparison with discharge plasma formation are discussed. It is shown that the formation of excimer molecules is an important process. This paper summarizes various studies of particle beam induced light emission and presents the first results of a direct comparison of light emis...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2003